Notes taken during lecture

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Published on 30 Mar 2011
School
UTSG
Department
Biology
Course
BIO120H1
LECTURE 22
C-cadherin and integrin feed into cell cell to cell contact cell know if other cells
around, modifying cell proliferation
Myc = growth factors through receptor tyrosine kinases regulating myc expression,
which regulates cell cycle
Cyclin B brings cell up to DNA synthesis
P53 and p21 = DNA damage center
All human cancers have Rb misregulation and P53, especially Rb misregulation or mutation
There are ~10 to the power of 14 cells in the human body
Small percentage of these cells divide, make two daughter cells
Every time cell divides, DNA replication is imperfect
Also cosmic rays and radiation
All of which can cause mutation
Body can recognize that and cell undergoes programmed cell death, and its
removed from system
Cancer develops from one of these cells
Excess proliferation
Cells need to divide too much and to escape cell death to be good cancer cells
oCollection of mutations allow this
oImmortalized
oTumour cells are immortal actual term
oGrow tumour cells in tissue culture, will divide indefinitely
Females are mosaics due to X inactivation
oCluster of normal cells mixture
oLook at tumour, all of the cells have same inactivated X chromosome
oEvidence that ONE cell turned into whole tumour
(exponential growth)
oAs long as nutrients is sufficient
oLarge enough to be visible on X-ray
oAlready around for quite a long time
oHow do tumours kill people?
Get too big and push on something important, cut off circulation of
something important
o24 hours in cell cycle at maximum rate of division
How long would it take the tumour to be too big
Tumour
Uncontrolled proliferation -> mass of abnormal cells
Neoplasm = new growth
Based on type of originating tissue
oCarcinomas
oBenign tumour not all benign tumours pass onto next stage
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Document Summary

C-cadherin and integrin feed into cell cell to cell contact cell know if other cells around, modifying cell proliferation. Myc = growth factors through receptor tyrosine kinases regulating myc expression, which regulates cell cycle. Cyclin b brings cell up to dna synthesis. All human cancers have rb misregulation and p53, especially rb misregulation or mutation. There are ~10 to the power of 14 cells in the human body .  small percentage of these cells divide, make two daughter cells.  every time cell divides, dna replication is imperfect.  body can recognize that and cell undergoes programmed cell death, and its removed from system.  get too big and push on something important, cut off circulation of something important: 24 hours in cell cycle at maximum rate of division.  how long would it take the tumour to be too big.  uncontrolled proliferation -> mass of abnormal cells .